OLIG2 and neoplasm: Sox-2, Olig-2 and GFAP were present at high levels in proliferative cells and expressed in the invasive part of the tumor, and T121 staining confirmed suppression of RB (Fig. 1, Sox-2, Sox-2/I, Olig-2, Olig-2/I, T121, T121/I and GFAP, GFAP/I).